Graphene is difficult and expensive to mass produce, but while trying to make something else altogether, Kansas State University (KSU) scientists may have lucked into a promising technique. The team was attempting to make carbon soot aerosol gels by detonating acetylene gas and oxygen with a spark plug. That yielded soot resembling "black angel food cake," according to lead researcher Chris Sorensen. It proved to be graphene, a discovery that could pave the way for cheaper manufacturing of lightweight but incredibly strong materials, superconductors, and more.
Graphene consists of bonded carbon that's just one atom thick, making it one of the lightest, strongest materials out there. It also has interesting electrical properties and has shown tons of experimental promise for rapid-charging "supercapacitor" batteries, solar cells and superconductors. However, more widespread use is limited by its cost -- methods like chemical "cooking" and high temperature heating have proven to be low-yield, expensive and even dangerous.
The KSU team's technique simply requires an oxidizing agent like oxygen or air, acetylene or other hydrocarbons and a spark, according to a patent it filed. The resulting detonation creates a 3,000 degree K temperature inside the vessel, enough to create pure graphene stacked in single, double or triple sheets. "What might be the best property of all is that the energy required to make a gram of graphene through our process is much less than other processes because all it takes is a single spark," Sorenson said.
The researchers are now working to improve the quality of the graphene and scale it up to industrial levels. The aim is to get the material out of the chamber several seconds after the detonation, so it doesn't form into an aerogel. However, the technique seems far along along already compared to other types of promising research, which often never leaves the lab. "The real charm of our experiment is that we can produce graphene in the quantity of grams rather than milligrams," says post-doc researcher Arjun Nepal.